here (https://www.thevespiary.org/rhodium/Rhodium/chemistry/equipment/calcium.hcl.generator.html)
(https://www.thevespiary.org/rhodium/Rhodium/chemistry/equipment/calcium.hcl.generator.html), they are preparing gasseous HCl by almost the same method. They dehydrate the hydrogenchloric acid with calciumchloride, thus liberating the free HCl in it's gas form.What kind of losses are you experiencing by drying the ether over MgSO4 (instead of drying the gas in-line)[ I find it easyer than drying the gas line, that's all, usual the etherr will contain some % wather.
For the strength part i mix 10mL ether with 100mL wather, stirr well and titrate the mixture with 1M NaOH and phenolphtaline.